Verification of using partial discharge localization algorithm based on sectional transfer functions of winding

Summary

Transformers are the most important and expensive apparatus in electric power systems and its health has a great effect on power quality, economic cost and reliability. There is a large number of researches aiming to improve transformer monitoring and failure detection. Partial discharge is a significant indication of insulation degradation, and affects the lifespan of power transformers. Partial discharge in power transformers could be critical depending on the amount of charge and especially on the location of the partial discharge source within the power transformer. Partial discharge localization via sectional transfer functions of power transformer winding was established long time ago at the Schering-Institute but the uncertainty concerning the location of the partial discharge source was still insufficient. This contribution focuses on verification of proposed partial discharge localization algorithm on power transformers using simulated sectional transfer functions of high voltage winding based on design information of the winding by injecting the partial discharges with laboratory setup. The simulation of windings through multi conductor transmission line method and its equations have been performed for a distribution transformer as a real case in the laboratory of Schering-Institute. The investigated transformer has been modified in order to inject partial discharge pulses into different points of the high voltage winding. The calculated sectional transfer functions were used for processing partial discharge signals that have been measured on the investigated transformer with different high voltage test setup. Hereby the injected partial discharge measurements include corona, discharges in voids and surface discharges. The simulated and complementary measured results will be presented and discussed comprehensively in this paper. The error ranges (the uncertainty) of proposed algorithm shows that the proposed partial discharge localization algorithm can be used for real cases with an accepted range of error.

Additional informations

Authors

LEBER, CHAMBERS

Keywords

PD, Partial Discharge, Power Transformer, MTLM, PD Localization